The present invention relates to a torsionally elastic coupling or, more particularly, a leaf spring coupling.
The torsionally elastic coupling has a first or inner coupling or hub, and a second or outer coupling part or outer ring. The two coupling parts are connected elastically to each other by radially arranged leaf-spring assemblies. The leaf-spring assemblies comprise leaf springs of different length, which together define a body of homogeneous flexural stress. The leaf-spring assemblies are rigidly connected to the hub by means of wedge-shaped intermediate pieces that form part of the hub and that are arranged between neighboring leaf spring assemblies. The longest leaf spring in the assemblies engage movably into the outer ring.
One torsionally elastic leaf-spring coupling is disclosed in German Pat. No. 555,438. The mode of attachment of the leaf-spring assemblies to the hub is significant there. Seen in longitudinal section, along the axis of rotation, each leaf-spring assembly has a T-shaped base. The base is fitted along one of its sides in an annular recess in the hub and along the other of its sides in an annular recess in a cover ring. In order to prevent undesired travel of the leaf-spring assembly in the circumferential direction, a wedge-shaped intermediate piece is clamped between every adjacent pair of leaf-spring assemblies. This prior art construction is expensive because of the T-shape of the bases of the leaf spring assemblies and because a cover ring is necessary in addition to the hub.
In making modern leaf-spring couplings, fabricators attempt to employ rectangularly shaped leaf springs, since they are simpler to manufacture. Such springs can preferably be cut from strip material. Known couplings of this type, as shown in German Pat. No. 1,202,590, are developed in the following way. An outer ring, two sides discs, and intermediate pieces between which the leaf-spring assemblies are clamped are all rigidly connected together. The resilient ends of the leaf springs extend radially inward, so that the longest leaf springs engage grooves in the hub. The clamping of the leaf-spring assemblies in the outer ring is effected by pressing a conically shaped intermediate ring into the outer ring. The outer ring thus must also be conical on its inner side. These known couplings have proven satisfactory in operation. However, their cost of manufacture is very high due to the complicated construction for the clamping of the leaf-spring assemblies in the outer ring.